Public warning systems (PWSs) are mainly for forecasting events, e.g., earthquakes, hurricanes, and the like, to the public by distributing warning messages. PWSs transmit to base stations warning messages, warning areas, and conditions of transmitting the warning messages to make the base stations schedule and broadcast the warning messages in the warning areas specified by the PWSs.
FIG. 1 is a schematic diagram illustrating a method of implementing fast recovery of PWSs according to the related art.
Referring to FIG. 1, an evolved nodeB (eNB) 101 schedules and broadcasts warning messages from a cell broadcast center (CBC) 105. The warning messages are transmitted by the CBC 105 to base stations via a mobility management entity (MME) 104. A home evolved nodeB (HeNB) 102 is connected to a core network directly or via an HeNB gateway (GW). When the HeNB 102 is connected to the core network via an HeNB GW 103, the MME 104 transmits warning requests transmitted by the CBC 105 to the HeNB GW 103 connected to the HeNB 102, and the HeNB GW forwards the warning requests to the HeNB 102. The process of the HeNB 102 handling the warning messages is similar to that of the eNB 101. The HeNB GW 103 forwards messages from the core network to the HeNB 102, and transmits messages from the HeNB 102 to the core network. The MME 104 maintains mobility context, session context and security information of UEs, routes messages from the CBC 105 in the PWS to base stations specified in the messages, and routes messages from the base stations to the CBC 105. The CBC 105 maintains configurations of warning messages in the PWS, e.g., configurations regarding warning contents, warning areas, warning conditions, and the like, and selects an MME based on the warning areas to transmit messages to the base stations.
Since a base station or some or all cells of the base station may fail and restart, or the PWS service in some or all cells of base station is restarted, the CBC needs to obtain information of the restated cell(s) or of the restarted base station or the cell(s) or the base station where the PWS service is restarted to avoid warning messages being lost. The affected warning messages due to the restarted cell(s) or of the restated base station or restarted PWS service may be recovered by the CBC. The CBC may reload the warning messages to the restarted base station or the base station of the restarted cell(s) via the MME and inform the MME of the identity of the base station so that the MME can forward the warning messages to the specified base station based on the identity of the base station.
At present, the following difficulties are met with by an MME routing warning requests to base stations: when the base station is an HeNB and connects to the core network via an HeNB GW, the MME only knows the identity of the HeNB GW rather than the identity of the HeNB, thus it cannot identify the HeNB or the HeNB GW connected by the HeNB according to an index of the HeNB in the receiving a warning request.
Therefore, a need exists for a method of implementing fast recovery of PWSs.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.